Submarine transfer arrangement

ABSTRACT

A transfer submarine and a submerged structure are constructed to facilitate transfer of personnel. The submarine is provided with a tethered ball at the end of a cable, and the submerged structure has a capture platform which has a slot for receiving the cable and restraining the submarine so as to facilitate alignment of a depending chamber of the submarine and an upstanding chamber of the submerged structure. The depending chamber has a spherical outer surface and the upstanding chamber has a mating conical surface for forming a transfer chamber. A method is disclosed by virtue of which the transfer occurs at substantially atmospheric pressure.

United States Patent 72] Inventor Vincent R. Bailey Palm Beach, Fla. [21 Appl. No. 855,594 [22] Filed Sept. 5, 1969 [45] Patented Dec. 7, 1971 [73] Assignee Perry Oceanographics, Inc.

Riviera Beach, Fla.

[54] SUBMARINE TRANSFER ARRANGEMENT 13 Claims, 7 Drawing Figs.

[52] U.S.Cl 114/16 R, l 14/ 1 6.8 [51] Int. Cl B63g 8/00, B63g 8/24 [50] Field otSearch 114/16, 16.3,16.4, l6.5,16.6,16.7,16.8;61/69 [56] References Cited UNITED STATES PATENTS 2,077,477 4/1937 Hellman ll4/l6.8 3,045,622 7/1962 Kittredge et a1. 1 14/167 3,292,564 12/1966 Lehmann 114/16 FOREIGN PATENTS 282,208 2/1931 Italy 114/16.8

861,168 10/1940 France l14/l6.5

Primary Examiner-Trygve M. Blix Attorney-Raphael Semmes ABSTRACT: A transfer submarine anda submerged structure are constructed to facilitate transfer of personnel. The submarine is provided with a tethered ball at the end.of a cable, and the submerged structure has a capture platform which has a slot for receiving the cable and restraining the submarine so as to facilitate alignment of a depending chamber of the submarine and an upstanding chamber of the submerged structure. The depending chamber has a spherical outer surface and the upstanding chamber has a mating conical surface for forming a transfer chamber. A method is disclosed by virtue of which the transfer occurs at substantially atmospheric pressure.

PATENTED [1E8 719?:

SHEET 1 OF 5 k INVIM'OI VINCENT RBAILEY PATENTED DEC 71971 SHEET 2 [IF 5 mvzmon VINCENT BAILEY ATTOR N BY PATENTED 05c mm 3,625: 171

SHEET 3 BF 5 nwmwol VINCENT R. BAILEY .Y Q M PATENTED DEC 7 I97! SHEET 5 BF 5 FIG. 7

INVEN'IOR VINCENT R. BAILEY ATTORNEY 1 SUBMARINE TRANSFER ARRANGEMENT BACKGROUND OF THE INVENTION This invention relates to a submarine transfer arrangement, and, more particularly, to a means and method for transferring personnel to or from a submerged structure at substantially normal atmospheric pressures.

There has been recently considerable interest in experimentation with underwater habitation. To this end, submarine habitats have been constructed to provide a protected living space for personnel engaging in such experiments. In order to transfer personnel to and from the ocean's surface and the submerged structure, it is necessary that a transfer or "rescuet" submarine become linked up with the submerged structure to provide means whereby personnel may leave or enter the submerged structure. Although it is obviously desirable that this transfer occur with the personnel never subjected to more than normal atmospheric pressure, this is not easily accomplished when the transfer occurs at great depth.

It is also difficult to physically link up the transfer submarine and the submerged structure. Typically, in the prior art, the transfer submarine would have a depending chamber which would be adapted to become engaged with a structure surrounding an entrance hatch of the submerged structure, which might be a disabled submarine. In order to form an effective seal, it was essential that the rescue submarine be accurately aligned with the hatch before this engagement could be effected. To this end, complex and cumbersome expedients were adopted. For example, it has been proposed that a guide line or cable be secured to the hatch of the submerged structure, that this line be sent to the surface by attaching it to a buoy, and that this line be secured to and wound about a reel mounted within the rescue submarine, which would then be guided therealong.

SUMMARY OF THE INVENTION It is accordingly a principal object of the present invention to provide an improved submarine transfer arrangement.

A more particular object is the provision of a submarine transfer arrangement permitting transfer of personnel at approximately atmospheric pressure.

It is also an object of the present invention to provide an improved method of transferring personnel from a submerged structure to or from a transfer submarine at atmospheric pressure.

An additional object of the invention is the provision of improved and relatively simple means for facilitating the capture of a transfer submarine by the submerged structure.

A further object of the invention is the provision of improved means for aligning the depending chamber of the transfer submarine with an upstanding chamber of the submerged structure.

Another object is the provision of mating chambers for the transfer submarine and the submerged structure which are so constructed as to reduce the necessity for accurate alignment.

Briefly, according to the present invention, the transfer submarine is provided with a tethered ball positioned at the end of a cable secured to the transfer submarine. The submerged structure has a submarine capture platform provided with an alignment slot having a wide V-shaped throat extending from one end and terminating in a narrow slot having a width which is large enough to receive the cable and small enough to restrain the tethered ball therebeneath. The transfer submarine has a depending chamber having a spherical outer surface, while the submerged structure is provided with an upstanding chamber having a conical mating ring adapted to engage the outer spherical surface of the depending chamber to form therewith a transfer chamber. A sealing ring of elastomeric material is placed on the conical mating ring so as to seal off the transfer chamber from the surrounding water. By virtue of the spherical outer surface of the depending chamber, it need not be accurately aligned with the upstanding chamber to provide an effective seal.

According to the method of the invention, a transfer submarine is captured by the submerged structure by maneuvering the submarine to bring the tethered ball into engagement with the slot on the capture platform so that the ball is positioned therebeneath and the cable extends upwardly through the narrow portion of the slot. The position'of the end of the slot and the length of the cable are such that the depending and upstanding chambers of the submarine and submerged structure may now readily be aligned and brought into engagement. After the sealing ring of elastomeric material is engaged against the outer spherical surface of the depending chamber, the pressure within the transfer chamber thus created is reduced to atmospheric pressure. Any remaining water in the transfer chamber is then drained or pumped off. Hatches to the transfer submarine and submerged structure are then opened, permitting personnel to transfer from one to the other at atmospheric pressure. The hatches are then closed, and the transfer chamber is again exposed to the water of the surrounding sea until it again reaches the ambient pressure. The submarine is then lifted ofi the upstanding chamber and moved in a direction to disengage the tethered ball from the capture platform. The submarine then travels to the surface to a mother ship where personnel are pennitted to leave the transfer submarine.

The foregoing and other objects, advantages, and features of the invention and the manner in which the same are accomplished will become more readily apparent upon consideration of the following detailed description of the invention when taken in conjunction with the accompanying drawings, which illustrate preferred and exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment of the invention showing a transfer submarine approaching a submerged structure;

FIG. 2 is a partial perspective view, partly in section, showing details of the first embodiment of the invention;

FIG. 3 is an enlarged exploded view of a detail of the embodiment of FIG. 1;

FIG. 4 is a section view taken generally along the line 4-4 of FIG. 5 showing a second embodiment of the invention with the transfer submarine engaged with the submerged structure;

FIG. 5 is a section view taken generally along line 55 of FIG. 4; I

FIG. 6 is a partial section view showing a detail of the embodiment of FIG. 4; and

FIG. 7 is a schematic diagram illustrating the method of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, it will be seen that a transfer submarine 10 is employed for taking personnel to and from the ocean's surface to a submerged structure or submarine habitat l2, which, as illustrated, is positioned by means of legs 14 on the ocean bottom 16. Although, in this application, the invention will be described with particular reference to such a submerged habitat or structure, it is to be understood that the inventionhas equal applicability to the transfer or rescue of personnel from a disabled submarine, provided that the submarine is equipped with the special apparatus of the present invention, or even a submerged oil well head chamber.

Returning to the transfer submarine 10, it will be observed that it comprises a generally cylindrical hull structure 18, having the usual upstanding conning tower 20 which, as is well known, will be employed for entry to and from the submarine when the submarine is at the surface. At one end of the submarine, it is equipped with a propeller 22 by means of which it may be driven through the water.

A special feature of the present invention is the provision of a tethered ball 24 which is secured to the hull 18 of submarine I0 by means of a painter cable 26. Turning to FIG. 3, it will be observed that cable 26, which may be made of %-inch wire rope, has an enlarged end 28 by means of which the tethered ball 24 is retained thereon. The tethered ball itself may be made of metal or some elastomeric material, such as rubber. It will be observed that cable 26 is secured to the hull of the submarine by means of a pin and clevis mechanism. Thus, the fixed end of cable 26 is received in an end fixture 30 having an aperture 32 for receiving a pin 34 which cooperates with the clevis 36 and is suitably retained thereon. The clevis, in turn, is mounted on and depends from the bottom surface of hull 18 of submarine 10.

As will be evident from FIGS. 1 and 2, submarine has a depending chamber 38 having an outer spherical surface. It will be noted that depending chamber 38 communicates with the interior of submarine 10 through a hinged hatch 40 (shown closed in FIG. 2). As will be seen in FIG. 7, a second outer hinged hatch is provided beneath hatch 40, pivoting, when open, downwardly within chamber 38. The inner hatch 40 is designed to resist the flow of atmospheric air from submarine 10 when the pressure inside the submarine is greater than the pressure outside. The outer hatch is designed to resist the pressure when the pressure outside the submarine is greater than the internal atmospheric pressure. The bottom end of depending chamber 38 has an access opening 42.

It is an important object of the present invention to capture submarine 10 and bring depending chamber 38 into alignment and engagement with a corresponding structure upstanding from the submerged habitat 12. To this end, as shown in FIG. 1, a flat landing or capture platform 44, having a generally Y- shaped slot 46 extending from one end thereof, is positioned above submerged structure 12. The slot has a first V-shaped portion 48 having a wide mouth at the end of platform 44 which tapers inwardly to a relatively narrow slot 50, forming the stem of the Y. Platform 44 is supported above submerged structure 12 by a plurality of pillars or struts 52, two of which are shown in FIG. 1. However, it is to be understood that at least four of these supporting struts are employed adjacent the four corners of platform 44. To afford access to submerged structure 12, platform 44 is provided with a circular opening 54. Returning to FIG. 2, it will be noted that submerged structure 12 has an upstanding, generally cylindrical, chamber 56. This chamber surrounds an access opening 58 to submerged habitat 12, which is covered by a hinged hatch 60. The upper end of upstanding chamber 56 has an access opening 62 which is surrounded by a mating ring 64 having an inwardly facing conical surface 66. As is best seen in FIG. 7, ring 64 may be provided as an integral conical flange. A sealing ring 68 of elastomeric material is positioned oh conical surface 66 so as to engage the outer spherical surface of depending chamber 38 and thus form a transfer chamber between the transfer submarine 10 and the submerged structure 12. It will be observed, also, that a bumper ring 70 of some suitable resilient material is mounted in a position surrounding mating ring 64 and, as will be seen from FIG. 1, fits within circular opening 54 of platform 44. If the chambers 38 and 56 are not in line when the initial contact is made, bumper ring 70 will absorb the reaches the Y-shaped slot 46. At this time, the ball will fall through the V-shaped portion of the slot and drop below platform 44. The direction of submarine movement will then be reversed to bring cable 26 into the stem portion 50 of the slot until the cable engages the end of slot 50. Since ball 24 is now below platform 44, the motion of transfer submarine 10 will be restricted in this reverse direction. The dimensions of cable 26 and the location of its point of attachment to the hull of submarine 10 are so selected that the distance between tethered ball 24, when the cable 26 is engaged with the end of the slot 50, and the centerline of depending chamber 38, when the latter is properly positioned above the submerged habitat 12, will be substantially equal to the distance between the end slot 50 and the centerline of upstanding chamber 56 of submerged habitat 12. This will enhance alignment of depending chamber 38 and upstanding chamber 56 so that they may readily become engaged by lowering submarine 10 toward submerged habitat 12 after the tethered ball is secured below the end of slot 50. With cable 26 held taut, submarine 10 is, in effect, pivoted about the end ofslot 50.

Referring again to FIG. 2, it will be noted that a pump 72 is provided, which is coupled by means of flexible pipe 74 to the interior of depending chamber 38 and by means of a discharge pipe 76 to a discharge duct opening from submarine 10 to the open sea. It will also be observed from FIG. 2, that a drain pipe 78 is provided from the bottom of upstanding chamber 56 to discharge through a valve 80 into the interior of submerged habitat 12. It will be understood that a bilge pump normally supplied in submerged structure 12 will then pump the drainage water into the open sea.

A second embodiment of the invention is shown in FIGS. 4, 5 and 6. Referring first to FIG. 4, it will be noted that a transfer submarine or submersible vessel is provided with a propeller 92 at the bow end to serve as a bow thruster and a stern thruster 94 at the other end. The usual conning tower 96 is upstanding from the top surface of submarine 90 and, in accordance with the present invention, a depending chamber 98 having an outer spherical surface is provided. An inner hinged hatch 100 closes off access to depending chamber 98, and a second outer hinged hatch 102 is also provided. As seen in FIG. 4, both of these hatches are open. The lower end of depending chamber 98 has an access opening 104.

This embodiment of the invention differs from the embodiment already described in that battery pod 106 is provided depending from the main hull I08 of submarine 90. This pod also provides more reliable spacing of the hull with respect to the landing platfonn. In this embodiment, the painter cable I 10 supporting tethered ball 112 is secured to the end of pod 106 by means of a pin and clevis arrangement 114.

As observed in FIG. 4, the submerged structure or habitat 120 is resting directly upon the ocean bottom 122. In this embodiment, as in the embodiment of FIGS. I-3, a capture or landing platform 124 is employed supported by a plurality of posts 126 extending from the top surface of structure 120. Platform 124 is again provided with a slot 128 having the same configuration as slot 46 in FIG. I. As shown in FIG. 4, cable is engaged with the end of the slot with tethered ball I12 positioned below platform 124.

' An upstanding chamber 130 is provided from the top surface of structure 120, surrounding a hatch opening 132 which may be closed by a hinged hatch 134. The upper edge of chamber 130 is provided with a mating ring 136 which has an inwardly facing conical surface 138, as can best be seen in FIG. 6. Surface 138 is provided with a groove 140 within which is received a sealing ring 142 of elastomeric material extending somewhat beyond surface 138. Mating ring 136 surrounds an access opening 144. As will be best seen in FIG. 5, a drain pipe 146 communicates with the lower end of chamber 130 so as to drain water therefrom through a valve 148. This water will typically be drained into submerged structure from which it will be pumped by a bilge pump.

Referring again to FIG. 4, it will be noted that when depending chamber 98 and upstanding chamber are mated with the spherical outer surface of chamber 98 engaged by the conical sealing surface of mating ring 136, a transfer chamber 149 is created, which will be sealed off from the surrounding sea water. Because of the fact that a spherical surface is mated to a conical surface, slight misalignment will be tolerated; an effective seal will be provided so long as the spherical surface engages with sealing ring 142 with a line contact.

It will be observed also from FIG. 4 that a pump 150 is coupled through a valve 152 by means of a flexible pipe 154 to the interior of transfer chamber 149. Pump 150 has a discharge pipe 156 which discharges fluid from the transfer chamber through discharge valve 158.

A bumper ring 160 is provided about mating ring 136 to cushion collisions between depending chamber 98 and upstanding chamber 130 before they are engaged in a sealing relationship as shown in FIG. 4.

The operation of both embodiments of the invention will best be understood from a detailed description of the method of the invention with particular reference to FIG. 7. It is to be understood that although the transfer submarine and submerged structure shown in the diagrams of FIG. 7 most closely resemble the embodiment of FIGS. 1, 2 and 3, the method shown therein has equal applicability to both embodiments.

Referring to FIG. 7, diagram a, it will be noted that submarine 10 is loaded aboard a mother ship 162. When the submarine is so located, personnel may climb inside the submarine from the deck of the ship. As seen in diagram b, submarine 10 is then launched from the mother ship with the personnel aboard. This may be accomplished by lowering the submarine to the surface of the sea where it is released and, in itself, becomes a surface vessel. As indicated in diagram 0, the submarine 10 then travels away from the mother ship, traversing across the surface of the sea to some desired location. As indicated in diagram d, submarine 10 will then dive, that is, move from the surface to a submerged position. The submarine is now operating near the bottom or on its way to the bottom of the sea. The next operation is an approach operation as illustrated in diagram e. The submarine is now approaching or searching for the submerged structure, which as indicated above, may be a fixed submarine habitat or, in a rescue operation, may be a disabled underwater vessel.

It is now necessary that the transfer submarine be captured by the submerged structure. Since the submarine has six degrees of freedom of motion-it can move forward, backward, up, down, to the right, or to the left, it is necessary to eliminate each of these degrees of freedom of motion in sequence in order to position the depending chamber of the submarine in engagement with the upstanding chamber of the submerged structure in such a manner that they are properly aligned and can be made pressure tight. Referring more specifically to diagram f, it will be seen that submarine 10 is now hovering over the submerged structure 12. In order to effect capture of the submarine, it is moved to a position above and slightly forward of the submerged submarine habitat 12. The tethered ball 24 is now positioned above landing platform 44. Submarine 10 is now lowered down so that the tethered ball 24 is positioned at an elevation lower than that of the platform 44. The submarine is now moved into position to bring cable 26 into the slot provided in platform 44 (see slot 46 in FIG. I). The submarine will now move backwardly, and the tethered ball will move beneath the slot with the painter cable 26 extending through the slot. The submarine will continue reverse movement until the cable 26 enters the narrow slot portion 50 of slot 46 (see FIG. 1) until further backward movement is restricted by the engagement of cable 26 with the end of the slot. At this instant of time, one of the degrees of freedom of the submarine (the reverse, or backward, direction of motion) is eliminated. It is now, however, still free to move up, to have its stem end rotate, to move down, to move to the right, to move to the left, or it can move forward. This situation, which may be characterized as the capture" position, is illustrated in diagram g. As shown in diagram g, the tethered ball is beneath the landing deck, and the submarine is above the landing platform. However, the depending and upstanding chambers of the submarine and submerged structure are not necessarily in alignment.

The next step of the procedure is to align the respective depending and upstanding chambers so that they will precisely locate themselves with respect to each other. To this end, the distance between the end of the slot in the landing platform and the centerline of the upstanding chamber of the submerged habitat must be the same distance as the distance from the tethered ball, when the cable 26 is engaged with the end of the slot, to the centerline of the depending chamber of the submarine, when it is properly positioned above the upstanding chamber of the submerged habitat. The submarine is then maneuvered by its propulsion thrusters and maneuvering thrusters into a position where the centerlines of the two chambers are aligned. This is the locate" operation as illustrated in diagram h. The submarine now rotates about the center of attachment of the tethered ball at the end of the slot of the landing platform. At this time, the submarine is maneuvered into such a position that the respective chambers attached to the submarine and the submerged structure come into intimate contact. This is the "set down" operation and is illustrated in diagram i.

Turning now to diagram j, which shows an enlarged view of this intimate contact between depending chamber 38 and upstanding chamber 56, itwill be observed that sealing ring 68 which is mounted on the conical surface of mating ring 64, if in intimate contact with the outer spherical surface of depending chamber 38, sealing it off from the surrounding sea water. It will be noted that the transfer chamber 163 created by the intimate engagement of depending chamber 38 and upstanding chamber 56 is now full of sea water. This water is at pressure which is equal to the submergence pressure (the pressure of the sea at that depth). The submarine is still free to maneuver; it now has four degrees of freedom. It can move up, forward, right or left. The downward movement, however, is restricted by the engagement of the depending chamber 38 with the sealing ring of the upstanding chamber 56.

It is now necessary to equalize the pressure inside submarine l0 and submerged structure 12 (which is substantially normal atmospheric pressure), with the pressure in the transfer chamber. Typically, the pressure in the transfer chamber may now be in the order of 300 to 400 pounds per square inch, absolute, while the pressures inside the submarine and the submerged structure would be of the order of 15 pounds per square inch, absolute, but could be as great as 30 pounds per square inch. In order to make these two pressures equal, a valve is opened exposing transfer chamber 163 to the pressure within the submarine. This is accomplished by first opening inner hatch 40 to expose an outer hatch 164. A valve 166 communicates with an opening through outer hatch 164. This valve is now open so as to equalize the pressures of submarine 10 and transfer chamber 163. Since the volume of the submarine is very much larger than the volume of transfer chamber I63, the pressure within transfer chamber I63 will soon become equalized with the pressure within submarine 10. As the pressure within transfer chamber 163 is equalized, the seal between sealing ring 68 and the outer spherical surface of depending chamber 38 will now be acted upon by an external force which is equal to the area of the surface of contact times the pressure of submergence of the hull at that particular depth of submergence. This additional pressure on the seal will greatly enhance its sealing effectiveness, locking chamber 38 against ring 68.

Once the internal pressures of the submarine l0, habitat l2, and transfer chamber 163 reach approximately 15 pounds per square inch, and are equal, all of the hatches can be opened. However, when outer hatch 164 is open, it will be observed that the transfer chamber I63 will still be full of water. This water is removed in a pumpdown operation as shown in diagram k. A flexible hose 74 is coupled to drainage pump 72 which pumps the water within transfer chamber 163 through a valve 168 to a discharge pipe. Since this operation is primarily performed to remove the water from the transfer chamber 163, it can also be effected by opening drain valve (see FIG. 2) and draining the water into the submerged structure. This particular expedient is also shown in the embodiment of FIG. 4, where a drain pipe 146 is provided for this purpose. While the pump shown in diagram k, is within the submarine, it is to be understood that this pumping could be effected by a pump located within the submerged structure 12.

When the water has been completely pumped out, or drained out, as the case may be, an access-transfer operation may be effected. This is illustrated in diagram 1. As shown in this diagram, all of the hatches are open, and a ladder 170 has been positioned from the opening into submarine 10 to the interior of the submerged structure 12. Personnel 172 are shown climbing up and down the ladder to transfer from one structure to the other. After the personnel have been transferred and any other business has been terminated, the transfer submarine will now prepare to return to the surface.

To initiate the return, it is first necessary to perform the steps illustrated in diagram m. The submerged habitat hatch 60 is first closed and the transfer chamber 163 is filled with water. The outside and inside hatches 164 and 40 of submarine 10 are then closed. Transfer chamber 163 is additionally flooded with water until it is completely filled with water. Chamber 163 is then connected to the outside sea by means of opening a suitable valve (not shown). The pressure within transfer chamber 163 will thus become equalized with the pressure of the surrounding sea. At the time the pressure in the transfer chamber 163 reaches the ambient pressure of the surrounding sea, the force between depending chamber 38 and sealing ring 68 of upstanding chamber 56 is now reduced to only the weight of the submarine. The submarine is now free to have four degrees of freedom-forward, upward, and to either side. The submerged structure 12 is preventing downward motion. Due to the engagement of the tethered ball in the slot of the platform 44, the submarine still cannot move backwards.

in the next step illustrated in diagram n, the submarine is lifted off. The lift-off operation consists of applying power to a vertical thruster which provides a force to overcome the force of gravity, holding the submarine down upon the habitat. This will cause an upward motion and a rotation about the tethered ball at the point of rotation at the end of the slot. This motion need be only 4 or 5 inches of motion. Chambers 38 and 56 will now disengage themselves to destroy transfer chamber 163. The submarine will now be free in five directions of motion up, down, port, starboard and forward. At this point, vehicle power is put on the main thruster or main propulsion unit of the submarine, and the submarine moves forward. As it moves forward, the cable 26 and tethered ball 24 can now move out of the slot in landing platform 44. The submarine is now released, as shown in diagram 0, and is capable of receding from its position adjacent underwater habitat 12. It is again a free submarine vehicle ready to return to the surface. This travel to the surface is illustrated in diagram p. The submarine then surfaces as illustrated in diagram q. it now moves back to a position adjacent mother ship 162 as shown in diagram r. A crane 174 on the mother ship may be employed for lifting the submarine to the deck of the mother ship. This position is shown in diagram s. Personnel are now free to leave the submarine as shown.

While preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes can be made without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims.

The invention claimed is:

l. A method of facilitating the transfer of personnel from a submerged structure having an upstanding chamber to a free, unguided submersible transfer vessel provided with conventional propulsion and maneuvering means and having a depending chamber and a cable depending from said vessel, one end of said cable being fixed to said vessel and the other end of said cable being free, said structure including restraining means for restraining said free end of said cable, comprising:

approaching said structure with said vessel with said cable hanging free,

maneuvering said vessel by employing said propulsion and maneuvering means to engage said free end of said cable with said restraining means to restrain said vessel from movement in at least one direction, said cable being of such length and said free end being so positioned when engaged with said restraining means that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction about the center of attachment of said cable with said structure,

moving said vessel in said second direction by employing said propulsion and maneuvering means to engage said chamber depending from said vessel with said chamber upstanding from said structure to form a transfer chamber closed off from the surrounding water,

reducing the pressure within said transfer chamber to the pressure within said vessel and said structure,

draining water out of said transfer chamber, and

opening hatches from said vessel and said structure to said transfer chamber.

2. A method as recited in claim 1, further comprising the steps of:

closing said hatches,

opening said transfer chamber to the surrounding water to fill said transfer chamber with water at the pressure of the surrounding water,

disengaging said depending and upstanding chambers,

disengaging said cable from said restraining means,

and removing said vessel from the vicinity of said submerged structure.

3. A method as recited in claim 1, wherein said cable has a tethered ball at its free end and said restraining means includes a slot for receiving said cable with said ball thereunder.

4. A method as recited in claim 1, wherein said depending chamber has an outer spherical surface and said upstanding chamber has a conical surface adapted to engage with said outer spherical surface of said depending chamber.

5. In a system for transferring personnel from a submersible transfer vessel and a submerged structure, a cable depending from said vessel and having a free end, means for engaging said free end of said cable with said structure to restrain relative movement of said vessel and structure in one direction, a chamber depending from said vessel, and a chamber upstanding from said structure, said cable being of such length and said free end being so positioned when engaged by said means that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction to form a sealed transfer chamber therewith, said cable having a tethered ball at its free end and said structure being provided with a slot having a stem portion of width greater than said cable and smaller than said ball.

6. A system as recited in claim 5, wherein said structure comprises a plate in a substantially horizontal plane within which said slot is provided, said plate having a V-shaped entrance slot portion in said plane communicating with said stem portion to facilitate engagement of said slot with said cable, a space being provided below said plate for receiving said ball.

7. A system as recited in claim 5 wherein the end of said slot stem portion is so positioned with respect to the centerline of said upstanding chamber and said tethered ball is so positioned with respect to the centerline of said depending chamber that when said cable is engaged against the end of said slot stem portion with said tethered ball thereunder said depending chamber will be alignable with said upstanding chamber.

8. in a system for transferring personnel from a submersible transfer vessel provided with conventional propulsion and maneuvering means and a submerged structure, a cable depending from said vessel and having a free end, capture means on said structure for capturing said free end of said cable to restrain relative movement of said vessel and structure in one 9. A system as recited in claim 8, wherein one of said chambers has a spherical outer surface and the other of said chambers has a conical surface adapted to engage against said spherical outer surface so that said chambers may become engaged and form said transfer chamber.

10. A system as recited in claim 9, wherein said conical sur' face is provided with an elastomeric sealing ring to seal said transfer chamber by engaging against said outer spherical surface of said one chamber.

11. A system as recited in claim 9, wherein said one chamber is said depending chamber and said other chamber is said upstanding chamber.

12. Apparatus for facilitating the capture of a submersible vessel, having a depending cable with a tethered ball at its free end, by a submerged structure, comprising a capture platform in a substantially horizontal plane positioned above said submerged structure, said capture platform having at one end an alignment slot for receiving said tethered ball, said alignment slot having a relatively wide mouth in said horizontal plane, a generally V-shaped portion in said horizontal plane, and a narrow end portion, said V-shaped portion tapering inwardly from said mouth to said end portion and said end portion being of such width that it will receive said cable and being narrower than the diameter of said ball.

13. A method of facilitating the transfer of personnel from a submerged structure having an upstanding chamber to a free,

unguided submersible transfer vessel having a depending chamber comprising:

approaching said structure with said vessel,

maneuvering said vessel to engage a cable depending from said vessel with said structure to restrain said vessel from movement in at least one direction, said cable being of such length and said free end being so positioned when engaged with said structure that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction about the center of attachment of said cable with said structure,

moving said vessel in said second direction to engage said chamber depending from said vessel with said chamber upstanding from said structure to form a transfer chamber closed off from the surrounding water,

reducing the pressure within said transfer chamber to the pressure within said vessel and said structure,

draining water out of said transfer chamber, and

opening hatches from said vessel and said structure to said transfer chamber,

said submerged structure being provided with a capture platform having an alignment slot extending from one end thereof and having a narrow end portion, said cable having a tethered ball at its free end, and said step of maneuvering said vessel comprising positioning said vessel with said ball above and slightly forward of said one end of said capture platform, lowering said vessel to position said ball at an elevation lower than that of said platform, and moving said vessel backwardly of said platform to bring said cable into said slot with said ball beneath said platform and into engagement with the end of said narrow end portron. 

1. A method of facilitating the transfer of personnel from a submerged structure having an upstanding chamber to a free, unguided submersible transfer vessel provided with conventional propulsion and maneuvering means and having a depending chamber and a cable depending from said vessel, one end of said cable being fixed to said vessel and the other end of said cable being free, said structure including restraining means for restraining said free end of said cable, comprising: approaching said structure with said vessel with said cable hanging free, maneuvering said vessel by employing said propulsion and maneuvering means to engage said free end of said cable with said restraining means to restrain said vessel from movement in at least one direction, said cable being of such length and said free end being so positioned when engaged with said restraining means that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction about the center of attachment of said cable with said structure, moving said vessel in said second direction by employing said propulsion and maneuvering means to engage said chamber depending from said vessel with said chamber upstanding from said structure to form a transfer chamber closed off from the surrounding water, reducing the pressure within said transfer chamber to the pressure within said vessel and said structure, draining water out of said transfer chamber, and opening hatches from said vessel and said structure to said transfer chamber.
 2. A method as recited in claim 1, further comprising the steps of: closing said hatches, opening said transfer chamber to the surrounding water to fill said transfer chamber with water at the pressure of the surrounding water, disengaging said depending and upstanding chambers, disengaging said cable From said restraining means, and removing said vessel from the vicinity of said submerged structure.
 3. A method as recited in claim 1, wherein said cable has a tethered ball at its free end and said restraining means includes a slot for receiving said cable with said ball thereunder.
 4. A method as recited in claim 1, wherein said depending chamber has an outer spherical surface and said upstanding chamber has a conical surface adapted to engage with said outer spherical surface of said depending chamber.
 5. In a system for transferring personnel from a submersible transfer vessel and a submerged structure, a cable depending from said vessel and having a free end, means for engaging said free end of said cable with said structure to restrain relative movement of said vessel and structure in one direction, a chamber depending from said vessel, and a chamber upstanding from said structure, said cable being of such length and said free end being so positioned when engaged by said means that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction to form a sealed transfer chamber therewith, said cable having a tethered ball at its free end and said structure being provided with a slot having a stem portion of width greater than said cable and smaller than said ball.
 6. A system as recited in claim 5, wherein said structure comprises a plate in a substantially horizontal plane within which said slot is provided, said plate having a V-shaped entrance slot portion in said plane communicating with said stem portion to facilitate engagement of said slot with said cable, a space being provided below said plate for receiving said ball.
 7. A system as recited in claim 5 wherein the end of said slot stem portion is so positioned with respect to the centerline of said upstanding chamber and said tethered ball is so positioned with respect to the centerline of said depending chamber that when said cable is engaged against the end of said slot stem portion with said tethered ball thereunder said depending chamber will be alignable with said upstanding chamber.
 8. In a system for transferring personnel from a submersible transfer vessel provided with conventional propulsion and maneuvering means and a submerged structure, a cable depending from said vessel and having a free end, capture means on said structure for capturing said free end of said cable to restrain relative movement of said vessel and structure in one direction, a chamber depending from said vessel, and a chamber upstanding from said structure, said cable being of such length and said free end being so positioned when captured by said capture means that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction by employing said propulsion and maneuvering means to form a sealed transfer chamber therewith.
 9. A system as recited in claim 8, wherein one of said chambers has a spherical outer surface and the other of said chambers has a conical surface adapted to engage against said spherical outer surface so that said chambers may become engaged and form said transfer chamber.
 10. A system as recited in claim 9, wherein said conical surface is provided with an elastomeric sealing ring to seal said transfer chamber by engaging against said outer spherical surface of said one chamber.
 11. A system as recited in claim 9, wherein said one chamber is said depending chamber and said other chamber is said upstanding chamber.
 12. Apparatus for facilitating the capture of a submersible vessel, having a depending cable with a tethered ball at its free end, by a submerged structure, comprising a capture platform in a substantially horizontal plane positioned above said submerged structure, said capture platform having at one end an alignment slot for receiving said tethered ball, said alignment slot having a relatively wide mouth in said horizontal plane, a generally V-shaped Portion in said horizontal plane, and a narrow end portion, said V-shaped portion tapering inwardly from said mouth to said end portion and said end portion being of such width that it will receive said cable and being narrower than the diameter of said ball.
 13. A method of facilitating the transfer of personnel from a submerged structure having an upstanding chamber to a free, unguided submersible transfer vessel having a depending chamber comprising: approaching said structure with said vessel, maneuvering said vessel to engage a cable depending from said vessel with said structure to restrain said vessel from movement in at least one direction, said cable being of such length and said free end being so positioned when engaged with said structure that said depending chamber is engageable with said upstanding chamber upon movement of said vessel in a second direction about the center of attachment of said cable with said structure, moving said vessel in said second direction to engage said chamber depending from said vessel with said chamber upstanding from said structure to form a transfer chamber closed off from the surrounding water, reducing the pressure within said transfer chamber to the pressure within said vessel and said structure, draining water out of said transfer chamber, and opening hatches from said vessel and said structure to said transfer chamber, said submerged structure being provided with a capture platform having an alignment slot extending from one end thereof and having a narrow end portion, said cable having a tethered ball at its free end, and said step of maneuvering said vessel comprising positioning said vessel with said ball above and slightly forward of said one end of said capture platform, lowering said vessel to position said ball at an elevation lower than that of said platform, and moving said vessel backwardly of said platform to bring said cable into said slot with said ball beneath said platform and into engagement with the end of said narrow end portion. 